The invention relates to a device for receiving and separating chips and cooling liquid collecting on machine tools, the cooling liquid being returned for reuse and the chips being discharged, having a receiving tank for receiving the chips and the cooling liquid, a rising guide section adjoining the receiving tank, an elevated delivery section adjoining the guide section, a chain-like closed transport element which, at least in the region receiving the chips and the cooling liquid and in the delivery section, is guided via deflecting elements, of which at least one is coupled to a rotary drive, and a rotatably mounted filter drum which is in drive connection with the transport element.
In a known device of this type (U.S. Pat. No. 6,332,983), a transport element is directed partly around the filter drum and directly causes this drum to rotate in the process. It follows from this that the bearings of the drum are radially loaded by the transport element, that is to say that the wear on these bearings increases. Furthermore, as a result of the direct drive connection between transport element and filter drum, the circumferential speed of the filter drum must always correspond to the speed of the transport element.
The object of the present invention, then, is to reduce the bearing load of the filter drum in a device of the type mentioned at the beginning and to make it possible for a filter cake to form on the outside on the circumference of the drum despite a continuously revolving transport element, this filter cake positively influencing the filter effect.
This object is achieved according to the invention in that the transport element is guided along the filter drum at a radial distance from the latter on guide rails, and in that cooperating driver elements acting only in the circumferential direction on the filter drum and arranged in each case at a distance from one another are provided on the transport element and on the filter drum.
In this case, the pressure exerted during the deflection of the transport element in the region of the filter drum is absorbed by the guide rails and the bearings of this drum are relieved. At the same time, the filter drum does not automatically follow the movement of the transport element. On the contrary, the arrangement of the cooperating driver elements on the filter drum on the one hand and on the transport element on the other hand determines the phases in which a rotation takes place and, on the other hand, in which the filter drum is stopped. During these stop periods, a filter cake can form in a perfectly desirable manner on the lateral surface of the filter drum, this filter cake increasing the filter effect. In a manner known per se, this filter cake can be dissolved from the inside of the filter drum by jets of filtered cooling liquid in order not to allow the thickness of the filter cake formed to increase too much.
The driver elements on the filter drum are expediently designed as projecting pins and the driver elements on the transport element are expediently designed as projecting stops cooperating with the pins.
Furthermore, provision is made according to the invention for the driver elements to have a crank mechanism, the crank of which is in drive connection with the transport element and the rod of which carries a driver element which engages in the tooth system of a ratchet wheel coupled to the filter drum. In this case, the crank radius of the crank mechanism can be adjustable. As a result, the angle by which the filter drum is advanced during a revolution of the crank can be determined.
Both drive variants can in each case be attached on one side or on both sides of the filter drum. On the one hand, the circumferential speed can be increased by the drives alternately driving the drum on both sides; on the other hand, torsional forces are avoided during synchronous drive of both drum sides.
Furthermore, the device according to the invention may be designed in such a way that the transport element is a scraper chain guided at its two sides in the housing of the device and having scraper webs running transversely to the transport direction and projecting downwards in the region of the bottom strand.
Furthermore, the invention provides for the transport element to be a hinged belt conveyor guided at its two sides in the housing of the device and having supporting sections running transversely to the transport direction.